1. Field of the Invention
The present invention relates to monolithically integrated linear image scanning circuits, and in particular to a circuit for readout of data therefrom.
2. Description of the Prior Art
A monolithically integrated circuit for linear image scanning having a linear image sensor with two parallel rows of opto-electronic sensor elements is known from "IEEE Transactions on Electron Devices, " Vol. ED-25, No. 2, February, 1978 at pages 125 through 131. As disclosed therein, the sensor elements in one of the rows comprise a first group which are disposed behind a color filter of a first type and the sensor elements in the other row comprise a second group which are disposed behind color filters of a second type. An array having a linear image sensor for scanning the images of a continuously moving 8 mm film, which supplies a television signal containing the information, is disclosed in BBC Report RD 1973/32 (PH-113) "Solid State Sensors: The Use of a Single Dimension 512 Element Array for Film Scanning," pages 1 through 17, published in November, 1973 by the British Broadcasting Corporation.
A known method of image scanning consists of initially scanning only a portion of the lines of an image, for example, the odd-numbered lines, which together generate a first partial or fractional image. During an image reproduction, this first partial image is supplemented by additional partial images which may be comprised, for example, of the even-numbered image lines, thereby forming a complete image. Such a method, which is customarily employed in image reproduction in television installations, is known as interlacing.
In known circuits utilizing the interlacing method, the individually successive integration times during which optically generated charges are formed in the sensor elements as a result of radiation incident thereon (data information) are controlled by a clock pulse voltage which may be connected either to a transfer gate disposed between the sensor element and a readout device or directly to the sensor element. The integration times virtually border one another, that is, the ending of one integration time essentially coincides with the beginning of the successive integration time. As a result, during a scanning operation by the interlacing procedure, the generated sensor signals do not precisely correspond to the image data of the groups of sensors such as the odd-numbered lines, but rather correspond to overlapping portions of the sensor lines, such as the first sensor and a portion of the second line, the third sensor and a portion of the fourth line and so forth. Due to the undesired components of the intermediate lines, which undesired components are unavoidably contained in the desired line signals in known arrangements, the resolution of the complete image generated by the number of partial images, is considerably impaired in the vertical direction.